This invention relates to improvements in buoys for mooring ships.
In U.S. Pat. Nos. 3,823,432 and 3,908,212, there are described and shown buoys with associated mooring yokes, which are attached to the buoys in such a manner that they form a rigid integral unit therewith. In one instance the mooring yoke is rigidly attached to the buoy which rotates in a bearing which surrounds the periphery of the buoy, and in the other instance the mooring yoke is attached, rigidly, to a turntable which rotates on the top of the buoy. The purpose for this type of coupling is indicated as being required because buoys with associated mooring arrangements of the type known in the prior art, which constitutes a yoke pivotably hinged with respect to a turntable on top of the buoy, are subjected to tidal and weather conditions which require the buoy to have a considerable adherent stability to cope with the forces exercised thereon by the mooring arrangement, which causes them to tip the buoy. To overcome this tipping proclivity, the buoy needs to have a relatively large mass, with the result that the forces to which the rigid coupling members coupling the buoys to the mooring arrangement are also of considerable magnitude.
It is indicated in the patent, that the buoy is coupled to the mooring arrangement in a manner which may be likened to the manner in which a wheel barrow is held by its user. The single wheel of the wheel barrow may be likened to the buoy and the two handles thereof to the coupling members, and the mooring arrangement to the user of the wheel barrow, such that any lateral roll of the ship is transferred to the buoy via the rigid coupling members in the same way that any lateral tilting of the barrow by the user will be transferred from the handles to the single front wheel. The benefit of these arrangements is that by essentially making the buoy and the yoke unitary, except for the pivoting capability, the requirement for the buoy to have a relatively large mass to provide inherent stability is considerably reduced, and the buoy's tendency to tip in response to these forces is also reduced.
A problem that arises in rigidly coupling the yoke to the turntable on a two-way bearing ring around the periphery of the buoy is that the portion of the yoke which is attached to the deck or to the bearing is very large, very cumbersome, and very expensive. Also, in view of the rigid coupling of the yoke to the buoy, there is no provision for adjustment of the yoke attitude relative to a moored vessel. Further, assembly of a yoke constructed in the manner described as well as removal of the yoke for any reason, is a complex and cumbersome job and requires removal of the bearing.